Closure fastener



Dec. 18, 1951 E,VJ ZELT 2,579,354

CLOSURE FASTENER B Filed Sept. 29. 1950 Inventor Elmer J. Zelt HisAtfiorn e y Patented Dec. 18, 1951 fElm'er J. Zelt, Fort Wayne, IndJas'signor' toGeneral Electric Company; a corporation of New York Application ea-Babe 29, 1950, seam. 187,482 j l o This invention relates to closure fasteners and, more particularly, to improvements in cover 2 Claims. (Cl. 220-60) fasteners for casings for small electrical devices,

such as ballasts for fluorescent lamps.

Heretofore covers for casings of the above mentioned type have been fastened in place by screws or rivets, thus requiring a separate fastening operation after the cover has been put in place over the opening in the main body portion of the casing.

In accordance with the present invention, there is provided a novel, simple and inexpensive snap fastener which automatically fastens the cover to the casing when the cover is pressed into place a over the opening in the main body of the casing,

thus entirely eliminating a separate cover fastening operation. In addition, the parts o1 'the fastener are integral with the main parts of the casing and cover and are formed therein at the time those parts are formed. Usually, the casing parts are made of sheet steel and they are stamped automatically to the proper shape.

An object of the invention is to provide a new and improved closure fastener.

Another object of the invention is to provide a new and improved snap action closure fastener.

An additional object of the invention is to provide a new and improved cover fastener for the casing of a relatively small electrical device. such as a ballast for fluorescent lamps.

The invention will be better understood by considering the following description taken in concasing embodying the present invention with a portion thereof shown broken away and in section. 1

Fig. 2 is an enlarged detailed perspective view for illustrating the operation of the "fastener shown in Fig. 1, Fig. 3 is a view similar to Fig. 2 showing. the parts locked or fastenedtogether, and Fig. 4 is an end view taken on line 4 4 of Fig. 3. v

Referring now to the drawing, and fiiore particularly to Fig. 1, there is shown thereinabasing consisting of a main tub-like body portionl and a flat cover member 2. The main portion is pro vided with a pair of outwardly extending oppositely disposed fiat end flanges 3 which lie in the same plane and the cover 2 is piovided w th ends 4 which overlie the flanges 3. Part of each end I of the cover member 2 consists of an'. integral projection 5 which is bent at substanti 1 y right angles to the plane of the cover 2 tow rd 2 the maincasing portion I. These projections 5 flt into openings 6 provided in the end flanges 3 of the main casing portion I.

As shown more clearly in Fig. 2, the projection 5 has a relatively long base I and a relatively short end 8 joined by tapering sides 9. In addition, there are notches I0 in the sides of the projection 5 adjacent to base 'I.

The general shape of the openings 5 is similar to that of the projections 5 and consists of a long inner end I I, a short outer end I2, and tapering sides IS. The length of the short end 8 of the projections 5 corresponds generally to the length of the short outer ends I2 of the openings 6 and, likewise, the length of the base I of the projections 5 corresponds generally to the length of the inner long ends I I of the openings 6.

The operation of the fastener is as follows. When the cover 2 is placed over the opening in the main tub-like portion I of the casing with the ends of the projections 5 entering the openings 5 as shown by the full line position of the projection 5 in Fig. 2, the tapering sides 9 of the projections 5 will engage the tapering sides I 3 of the openingsfi. If, now, pressure is applied forcing the cover down onto the flanges 3, the tapers of the projections 5 and the openings 5 will cause the projections to bend inwardly toward the main casing portion I as shown by the dashed line position of the projection 5 in Fig. 2'. This action will continue until the shoulders of the notches III pass through the openings 6 whereupon the projections 5 will snap outwardly to the position shown in Figs. 1 and 3 whereby the notches I5 embrace the sides I3 of the openings 6 and securelylock the cover in place.

It will thus be seen that the fastening or looking action 01. the fastener takes place automatically in the assembly of the device, that is to say, when the cover 2 is pressed into place on the main body portion I, and that no additional fastening operation is necessary.

If it is desiredf'to remove the cover 2, it is only necessary to bend the ends of the projections 5 inwardly until the shoulders of the notches Ill clear the sides of the openings 6.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and that it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as'new and'desire to'secure by the same plane and a flat cover member having Letters Patent of the United States is: ends which overlie said flanges, an opening in 1. In an electrical device casing of the type each flange having a lon i n r end an a Shor having a main tub-like portion with outwardly outer end joined by straight tapered sides, an extending oppositely disposed flat end flanges in 5 integral projection on each end of said cover exthe same plane and a flat cover member having tending substantially at right angles to the plane ends which overlie said flanges, complementary of said cover toward said main casing portion, shaped ifiterfittifigppenings andbrojfectionstonf eachrprotlectiorrhavings'azlongfldasewandia short said fiangesand cover 'ends, said projectic m's be"-- endijoined bystraight tapered sides'and-notches ing integral portions of said cover ends which are 10 in the sides of each projection adjacent its base, bent at substantially right angles to the plane ofizf this length of the base of each projection being said fiat cover toward said flanges. saidgprojec substantially equal to the long inner end of each tions having at least one notch in their sides ad fiange'opening, the'short end of each projection jacent the surface of said -cover-;=.,said--.eopenings:- A,QbQmSrSHbStaHtIEHX: equal to the length of the and. said projections being of$aperingconfigurae- 5:2 shortnuteniendfo each opening, said notches emtion and so spaced relative to each other that bracing the sideslof said flange openings for said notches embrace the edgesiof saidrecesses fasteningesaid cover in place.

for locking said cover in place. ELME'R J. ZELT.

2. In an electrical ballast casing of theweet 1 i; 1 having a main tub-likei portion with outwardly 20 No references cited.

extend-ingiroppositely disposedflanend-fiangesinz- 

